The present invention relates to a method of increasing the efficiency of feed utilization in swine during the grower and finisher phases of their growth cycle.
It is well known that the oral administration of certain organic compounds, for example 3-(2-quinoxalinyl-methylene)carbazate-N.sup.1,N.sup.4 -dioxide, and many antibiotics increases either the rate of growth or the efficiency of feed utilization in swine, and in some cases both effects are observed. While French Pat. No. 2,349,329 discloses the use of salinomycin for the treatment of gastrointestinal infections and for growth promotion in swine, it has heretofore been understood in the art that the effect of antibiotics on the rate of growth and efficiency of feed utilization in swine decreases with increasing age and size of the animals and is economically most significant in the starter phase of the animal's life i.e. from the time the pig is weaned to about 25 kg in weight. Accordingly, it has not heretofore been possible to fully realize the potential economic benefits of increasing the efficiency of feed utilization in swine during the later stage of the grower phase (i.e. from about 35 kg to about 60 kg body weight) and during the finisher phase (i.e. from about 60 kg to market weight) of the growth cycle by administration of an antibiotic.